FIG. 1 is views illustrating the steps of a method for manufacturing a conventional stabilizer bar, and FIG. 2 is a view illustrating a state in which the conventional stabilizer bar is mounted in place. Referring to FIG. 1, the conventional stabilizer bar 1 is manufactured by cutting a stabilizer bar material 12 having a round bar-shaped configuration with a circular cross-section, forming eyes 100 through forging both ends of the stabilizer bar material 12, and bending the stabilizer bar material 12 into the shape of a stabilizer bar 1. At this time, referring to FIG. 2, the leg bar 10 of the conventional stabilizer bar 1 is formed to have the same circular cross-section through the entire length thereof. The stabilizer bar 1 manufactured as described above is mounted such that the parallel bar 11 of the stabilizer bar 1 is secured with respect to a frame 3 via fasteners 2 in each of which a bush is fitted, and the leg bars 10 of the stabilizer 1 extend from both ends of the parallel bar 11 with the distal ends of the leg bars 10 connected to suspension arms (not shown). The stabilizer bar 1 is used to control a rolling phenomenon which occurs due to the tilt of a vehicle body. When the stabilizer bar 1 is mounted as described above, as can be readily seen from FIG. 2, a load P is applied to the distal end of each leg bar 10 due to the vibration of the vehicle body, whereby a moment is generated. As the moment is generated, a bending stress is generated in the leg bar 10. Since the leg bar 10 has the uniformly circular cross-section to have the same cross-sectional area and the same section modulus through the entire length thereof, the leg bar 10 has constant rigidity through the entire length thereof. Due to the fact that the leg bar 10 has constant rigidity through the entire length thereof, a stress is concentrated on a bent part 13 of the stabilizer bar 1 where the leg bar 10, in which a torsional stress is generated by the load P applied to the distal end of the leg bar 10, is connected to the parallel bar 11. Therefore, a problem is caused in that, when a load is repeatedly applied to the leg bar 10 for extended periods, the stabilizer bar 1 is likely to be broken at the bent part 13.